Condensed Consolidating Financial Information - Condensed Consolidating Balance Sheets (Detail) (USD $) In Millions, unless otherwise specified	May 31, 2014	Nov. 30, 2013	May 31, 2013	Nov. 30, 2012
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 120.7	$ 197.6	$ 134.6	$ 162.1
Accounts receivable	191.7	214.1
Inventories	131.9	105.9
Recoverable from the U.S. government, Northrop, and other third parties for environmental remediation costs	27.0	26.4
Other receivables, prepaid expenses and other	19.6	22.4
Income taxes	10.7	12.6
Deferred income taxes	16.2	17.0
Total Current Assets	517.8	596.0
Property, plant and equipment, net	370.6	374.7
Recoverable from the U.S. government and other third parties for environmental remediation costs	81.5	88.7
Deferred income taxes	170.2	175.7
Goodwill	164.4	159.6
Intercompany receivable	0	0
Investments in subsidiaries	0	0
Other noncurrent assets and intangibles, net	371.1	360.6
Total Assets	1,675.6	1,755.3
Short-term borrowings and current portion of long-term debt	4.2	2.9
Accounts payable	94.5	122.5
Reserves for environmental remediation costs	36.0	36.6
Income taxes	0	0
Other current liabilities and advance payments on contracts	289.2	310.4
Postretirement medical and life insurance benefits	7.2	7.3
Total Current Liabilities	431.1	479.7
Long-term debt	778.8	696.3
Reserves for environmental remediation costs	127.7	134.7
Pension benefits	252.7	261.7
Intercompany payable	0	0
Postretirement medical and life insurance benefits	57.5	59.3
Other noncurrent liabilities	76.8	73.8
Total Liabilities	1,724.6	1,705.5
Commitments and contingencies (Note 8)
Redeemable common stock	0.1	0.2
Total shareholders' (deficit) equity	(49.1)	49.6
Total Liabilities, Redeemable Common Stock and Shareholders' (Deficit) Equity	1,675.6	1,755.3
Eliminations [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	(4.6)	0	(1.3)	(10.3)
Accounts receivable	0	0
Inventories	0	0
Recoverable from the U.S. government, Northrop, and other third parties for environmental remediation costs	0	0
Other receivables, prepaid expenses and other	0	0
Income taxes	(11.9)	(17.5)
Deferred income taxes	0	0
Total Current Assets	(16.5)	(17.5)
Property, plant and equipment, net	0	0
Recoverable from the U.S. government and other third parties for environmental remediation costs	0	0
Deferred income taxes	0	0
Goodwill	0	0
Intercompany receivable	(265.2)	(103.7)
Investments in subsidiaries	(561.9)	(534.5)
Other noncurrent assets and intangibles, net	0	0
Total Assets	(843.6)	(655.7)
Short-term borrowings and current portion of long-term debt	0	0
Accounts payable	(4.6)	0
Reserves for environmental remediation costs	0	0
Income taxes	(11.9)	(17.5)
Other current liabilities and advance payments on contracts	0	0
Postretirement medical and life insurance benefits	0
Total Current Liabilities	(16.5)	(17.5)
Long-term debt	0	0
Reserves for environmental remediation costs	0	0
Pension benefits	0	0
Intercompany payable	(265.2)	(103.7)
Postretirement medical and life insurance benefits	0
Other noncurrent liabilities		0
Total Liabilities	(281.7)	(121.2)
Commitments and contingencies (Note 8)
Redeemable common stock		0
Total shareholders' (deficit) equity	(561.9)	(534.5)
Total Liabilities, Redeemable Common Stock and Shareholders' (Deficit) Equity	(843.6)	(655.7)
Parent [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	125.0	192.7	135.9	172.4
Recoverable from the U.S. government, Northrop, and other third parties for environmental remediation costs	0.1	0.4
Other receivables, prepaid expenses and other	4.5	2.6
Income taxes	22.1	30.1
Deferred income taxes	11.4	10.9
Total Current Assets	163.1	236.7
Property, plant and equipment, net	4.7	4.7
Recoverable from the U.S. government and other third parties for environmental remediation costs	0.7	0.4
Deferred income taxes	47.6	48.8
Intercompany receivable	234.2	71.5
Investments in subsidiaries	561.9	534.5
Other noncurrent assets and intangibles, net	30.2	27.7
Total Assets	1,042.4	924.3
Short-term borrowings and current portion of long-term debt	3.9	2.7
Accounts payable	2.5	2.2
Reserves for environmental remediation costs	2.3	3.8
Other current liabilities and advance payments on contracts	216.4	79.7
Postretirement medical and life insurance benefits	5.5	5.5
Total Current Liabilities	230.6	93.9
Long-term debt	778.2	695.7
Reserves for environmental remediation costs	4.3	4.3
Pension benefits	21.8	23.6
Postretirement medical and life insurance benefits	38.4	39.8
Other noncurrent liabilities	18.1	17.2
Total Liabilities	1,091.4	874.5
Commitments and contingencies (Note 8)
Redeemable common stock	0.1	0.2
Total shareholders' (deficit) equity	(49.1)	49.6
Total Liabilities, Redeemable Common Stock and Shareholders' (Deficit) Equity	1,042.4	924.3
Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	0	4.9	0	0
Accounts receivable	189.6	211.4
Inventories	126.1	100.5
Recoverable from the U.S. government, Northrop, and other third parties for environmental remediation costs	26.9	26.0
Other receivables, prepaid expenses and other	14.5	18.8
Income taxes	0	0
Deferred income taxes	3.6	4.9
Total Current Assets	360.7	366.5
Property, plant and equipment, net	360.0	364.4
Recoverable from the U.S. government and other third parties for environmental remediation costs	80.8	88.3
Deferred income taxes	103.5	107.2
Goodwill	164.4	159.6
Intercompany receivable	0	0
Investments in subsidiaries	0	0
Other noncurrent assets and intangibles, net	294.9	289.0
Total Assets	1,364.3	1,375.0
Short-term borrowings and current portion of long-term debt	0.3	0.2
Accounts payable	95.6	119.1
Reserves for environmental remediation costs	33.7	32.8
Income taxes	11.9	16.9
Other current liabilities and advance payments on contracts	70.3	227.9
Postretirement medical and life insurance benefits	1.7	1.8
Total Current Liabilities	213.5	398.7
Long-term debt	0.6	0.6
Reserves for environmental remediation costs	123.4	130.4
Pension benefits	230.9	238.1
Intercompany payable	265.2	103.7
Postretirement medical and life insurance benefits	19.1	19.5
Other noncurrent liabilities	46.7	45.1
Total Liabilities	899.4	936.1
Commitments and contingencies (Note 8)
Redeemable common stock		0
Total shareholders' (deficit) equity	464.9	438.9
Total Liabilities, Redeemable Common Stock and Shareholders' (Deficit) Equity	1,364.3	1,375.0
Non-guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	0.3	0	0	0
Accounts receivable	2.1	2.7
Inventories	5.8	5.4
Recoverable from the U.S. government, Northrop, and other third parties for environmental remediation costs	0	0
Other receivables, prepaid expenses and other	0.6	1.0
Income taxes	0.5	0
Deferred income taxes	1.2	1.2
Total Current Assets	10.5	10.3
Property, plant and equipment, net	5.9	5.6
Recoverable from the U.S. government and other third parties for environmental remediation costs	0	0
Deferred income taxes	19.1	19.7
Goodwill	0	0
Intercompany receivable	31.0	32.2
Investments in subsidiaries	0	0
Other noncurrent assets and intangibles, net	46.0	43.9
Total Assets	112.5	111.7
Short-term borrowings and current portion of long-term debt	0	0
Accounts payable	1.0	1.2
Reserves for environmental remediation costs	0	0
Income taxes	0	0.6
Other current liabilities and advance payments on contracts	2.5	2.8
Postretirement medical and life insurance benefits	0
Total Current Liabilities	3.5	4.6
Long-term debt	0	0
Reserves for environmental remediation costs	0	0
Pension benefits	0	0
Intercompany payable	0	0
Postretirement medical and life insurance benefits	0
Other noncurrent liabilities	12.0	11.5
Total Liabilities	15.5	16.1
Commitments and contingencies (Note 8)
Redeemable common stock		0
Total shareholders' (deficit) equity	97.0	95.6
Total Liabilities, Redeemable Common Stock and Shareholders' (Deficit) Equity	$ 112.5	$ 111.7